tetrabranchiate: Meaning and Definition of

tet•ra•bran•chi•ate

Pronunciation: (te"tru-brang'kē-it, -āt"), [key]
— adj.
  1. belonging or pertaining to the Nautiloidea (Tetrabranchiata), a subclass or order of cephalopods with four gills, including the pearly nautilus and numerous fossil forms.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.